Facebook is blocked in some offices and countries. If a website has a 'Like' button, it will turn gray (page not found in the iframe) to those viewers and it makes the page look broken.
Do you have any idea (maybe CSS method) to hide this gray area? When <iframe> is not loaded, it will show some other thing (like white color background) instead of showing a gray "dead" page?
The code for like button is like this:
<iframe src="http://www.facebook.com/plugins/like.php?href=your URL;layout=standard&show_faces=false&width=40&action=like&colorscheme=light&height=35" scrolling="no" frameborder="0" style="border:none; overflow:hidden; width:50px; height:35px;" allowTransparency="true">
</iframe>